ABSTRACT
The initial focus of the Brillouin optical time-domain analysis (BOTDA) work was to improve the range and accuracy of Optical Time-Domain Reflectometry (OTDR) by exploiting the optical gain provided by stimulated Brillouin scattering. Although it can be argued that the performance of a BOTDA system is a priori superior to that of a Brillouin optical time-domain reflectometer (BOTDR), the BOTDA range is in effect halved when deployed to monitor a linear object owing to the need for a looped sensing fibre. Since the development of these two techniques, a host of improvements have been described in the technical literature, and research is still active; the technology of Brillouin-based distributed sensing is the subject of chapter of this book. These trade-offs are discussed in the context of the various distributed optical fibre sensor (DOFS) technologies, but some more general points are made.
